经皮选择性肝脏隔离灌注化疗的实验研究

目的探讨经皮选择性肝脏隔离灌注化疗的可行性及隔离效果。方法将12只猪随机分为两组:HAI组6头,进行常规经肝动脉灌注化疗;PSIHP组6头,利用介入放射学方法进行经皮选择性隔离肝脏灌注化疗结合血液灌流。化疗药物选用5-FU。分别检测肝静脉及外周血液中的血药浓度,并对肝组织行病理学检查。结果HAI组右肝静脉血和外周静脉血浓度峰值分别为(4082.530±415.213)mg/L,(1682.230±216.834)mg/L;PSIHP组右肝静脉血、外周静脉血血药浓度峰值分别为(5321.711±517.318)mg/L,(510.834±52.518)mg/L。两组间有显著性差异(P<0.01)。PSIHP组过滤后肝静脉血血药浓度峰值为(1192.063±114.864)mg/L,碳肾率过滤达到(77.6±0.9)%。PSIHP组灌注区域肝脏组织损害程度比HAI组大。结论PSIHP是一种简单有效的肝脏隔离灌注化疗技术,与常规经肝动脉灌注化疗相比,不仅可以增加局部血药浓度,更可以降低外周的血药浓度,降低毒副作用。     

新型双球囊导管在经皮选择性隔离肝脏灌注化疗中的应用

目的探讨自制双球囊导管在经皮选择性肝脏隔离灌注化疗(PSIHP)中的应用效果。方法实验猪12头,利用介入放射学方法进行双球囊导管选择性隔离肝脏灌注化疗结合血液灌流。化疗药物选用5-FU。比较灌注及未灌注区域肝细胞形态和凋亡指数。结果灌注区域肝细胞损伤明显,肝细胞凋亡指数(51.82%±5.34%)明显高于未灌注区域肝细胞凋亡指数(4.12%±0.84%)(P<0.01)。结论自制新型双球囊导管能有效隔离肝脏,对未灌注区域肝组织有良好的保护作用,是一种理想的隔离肝脏灌注化疗的球囊导管。     

经皮选择性肝脏隔离灌注化疗肝细胞形态及凋亡研究

目的探讨经皮选择性肝脏隔离灌注化疗（PSIHP）的可行性及隔离效果。方法实验猪8头，利用介入放射学方法进行经皮选择性肝脏隔离灌注化疗结合血液灌流。化疗药物选用5-Fu。比较灌注及未灌注区域肝细胞形态和凋亡指数。结果灌注区域肝细胞损伤明显，肝细胞凋亡指数（52．83±5．12）明显高于未灌注区域肝细胞凋亡指数（3．52±0．96）（P〈0．01）。结论PSIHP是一种简单有效的肝脏隔离灌注化疗技术，隔离效果佳，对未灌注区域肝组织有良好的保护作用。     

逆行隔离灌注化疗可减轻对大鼠肝脏的毒性及药物的泄漏

目的 采用大鼠肝脏隔离灌注模型探讨逆行隔离灌注(RIHP)较顺行隔离灌注(IHP)能否减少正常肝组织损伤及化疗药物外周泄漏率.方法 将90只体重300～350 g雄性SD大鼠随机分为A、B、C三组,每组30只:A组为空白对照组,经肝动脉及门静脉灌注乳酸林格液,以下腔静脉为灌注液流出道;B组行IHP,经肝动脉灌注含有350 mg/kg的氟尿嘧啶(5-Fu),门静脉灌注乳酸林格液,以下腔静脉为灌注液流出道;C组行RIHP,经肝动脉灌注含有350 mg/kg的氟尿嘧啶(5-Fu),经下腔静脉灌注乳酸林格液,以门静脉为灌注液流出道.术后1、3、5、7 d分别行血清ALT测定及肝组织病理学检查;高效液相色谱分析仪检测B、C组术中外周血药浓度.结果 三组术后3 d存活率分别为90.0%、86.7%和90.0%,三者差异无统计学意义.三组血清ALT均在术后第一天达到峰值,A组为(481.6±207.6)μmol/L;B组为(1641.6±658.0)μmol/L;C组为(913.0±353.5)μmol/L.B、C组均显著高于A组(P＜0.05);B组显著高于C组(P＜0.05).B组与C组术中外周血药浓度峰值分别为(131.2±29.4)μg/ml和(65.3±28.4)μg/ml.两组外周浓度有显著性差异(P＜0.05).A组术后肝脏病理改变较轻,术后7 d基本恢复正常;B组术后肝脏病理学改变相对严重,术后7 d局部仍可见坏死灶;C组术后肝脏病理改变后较A组严重,但较B组轻,术后7 d基本恢复正常.结论 RIHP较之IHP能够显著减轻化疗药物对正常肝组织的毒副作用和药物的外周泄漏,有望成为一种对肝癌更加有效安全的区域化疗方法.     

HTK液逆行灌注可减轻肝脏隔离化疗对大鼠的损伤

目的:建立大鼠肝脏隔离灌注化疗模型;探讨在大剂量化疗药物肝脏隔离灌注过程中,HTK液经肝静脉逆行灌注对肝脏的保护及减少全身泄漏作用。方法:将75只体重300～350g的雄性SD大鼠随机分为3组,每组25只;手术建立大鼠隔离灌注化疗模型。A组经肝动脉灌注含30mg/L三氧化二砷的林格液,门静脉灌注林格液,肝静脉为流出道。B组经肝静脉灌注林格液,门静脉为流出道,余同A组。C组经肝静脉灌注4℃组氨酸-色氨酸-酮戊二酸(Histidine-Tryptophan-Ketoglutarat,HTK)液,余同B组。各组于术后1、2、3、7d各随机处死大鼠5只,进行血清肝功能及肝组织病理学检查。A组和B组大鼠术中检测体循环和肝循环中的血药浓度。结果:各组动物血清ALT和AST峰值均出现在术后第1天,其后开始下降,至术后7d恢复正常。术后第1、2、3d,3组间的血清ALT、AST均数均有显著性差异(P0.05);光镜下观察肝组织,进一步证实了上述结果。A组与B组间体循环血药浓度差异有统计学意义(P0.05),而两组间的肝循环血药浓度相类似;表明逆行隔离灌注的体循环泄漏率较顺行隔离灌注组为低。结论:低温HTK液逆行灌注可显著减轻肝脏隔离化疗对大鼠的损伤,提高手术的安全性。     

经肝动脉区域肝脏隔离灌注的研究

目的　研究幼猪经肝动脉区域隔离肝灌注的效果。　方法　14只幼猪随机分为2组:对照组(7只):采用经肝动脉灌注;实验组( 7只):左肝动脉及左肝静脉插管,进行左肝区域隔离肝灌注。灌注液为氨甲喋呤溶液(1mg/kg), 灌注时间为60min。于灌注5、10、20、30、45、60min时分别抽取外周血、肝脏灌注区域血、肝脏未灌注区域血(实验组)测定血药浓度; 灌注后切取左肝及右肝组织进行病理检查。　结果　在所有时间点, 实验组肝脏灌注区域氨甲蝶呤的血药浓度明显高于非灌注区和外周血(P<0. 01), 60min时最高, 达( 40. 211±3. 756 )μg/ml, 而非灌注区和外周血中仅为(1. 584±0. 347)μg/ml和(0. 773±0. 096)μg/ml。实验组灌注区域血药浓度均高于对照组肝脏血药浓度(P<0. 01), 60min时分别达(40. 211±3. 756)μg/ml和(4. 498±1. 643)μg/ml。实验组灌注区浓度-时间曲线下面积为218. 295μg/ml,而在对照组肝脏仅为260. 860μg/ml。病理检查提示两组灌注肝脏均有肝细胞浊肿、气球样细胞,但实验组肝脏灌注区域肝细胞坏死率为85. 7% (6 /7),明显高于对照组28. 6% (2 /7)。实验组肝脏未灌注区域无明显病理损害。　结论　动物实验证实经肝动脉区域隔离肝灌注是一种灌注及隔离效果好、肝功能损害小的区域化疗方法。     

半肝血流完全阻断无血肝切除术的临床研究

目的探讨半肝血流完全阻断下无血肝切除术的临床意义。方法对两组各14例原发性肝癌患者分别施行半肝血流完全阻断无血肝切除术（A组）和全肝入肝血流阻断肝切除术（B组）,比较两组患者术中肝血流阻断时间、术中出血量、肝切除体积、术后肝功能恢复情况、并发症发生率等指标。结果两组在肝血流阻断时间和肝切除体积无显著差异的条件下,A组的术中出血量平均为（296±240）ml,B组平均为（582±497）ml,两组比较差异有统计学意义（P〈0．05）。术后第1、3、7天血清前白蛋白水平A组为（164±39）mg／L、（111±17）mg／L和（104±23）mg／L,显著高于B组的（134±34）mg／L、（90±22）mg／L和（82±35）mg／L（P〈0．05）,两组其他观察指标差异无统计学意义（P〉0．05）。结论半肝血流完全阻断无血肝切除术能显著减少肝切除术中出血量及肝功能损害。     

介入性球囊导管技术在肝脏隔离灌注中应用的动物实验研究

肝脏隔离灌注 (ｉｓｏｌａｔｅｄｌｉｖｅｒｐｅｒｆｕｓｉｏｎ ,ＩＬＰ)是将肝脏所属主要血管游离阻断 ,并通过门静脉和(或 )肝动脉对肝脏进行隔离灌注。为了使技术简便易行 ,我们采用一种介入性球囊导管辅助隔离技术进行家猪的原位肝脏隔离灌注 ,现报告如下。1.材料与方法 :实验动物 :为健康家猪 12头 ,体重 2 3～ 35ｋｇ ,平均 2 8 9ｋｇ ,雌雄不限。主要试剂及仪器包括ＭｉｔｏｍｙｃｉｎＣ ,岛津ＬＧ 6Ａ型高效液相色谱等。随机分成 2组 ,Ａ组 (6只 ) :采用传统手术方法进行原位肝脏隔离灌注 ;Ｂ组 (6只 ) :采用球囊导管隔离技术进行灌…     

大鼠肝移植后早期血清一氧化氮的变化及其意义

目的探讨大鼠肝移植后早期血清一氧化氮（NO）的变化情况及其意义。方法将SD大鼠随机分成A、B、C三组，进行肝移植．供、受者均为SD大鼠。A组于移植肝恢复血流2h、B组于移植肝恢复血流4h、C组于移植肝恢复血流6h时采取受者的下腔静脉血和左肝叶组织．测定血清丙氨酸转氨酶（ALT）和NO含量．免疫组化法测定移植肝组织中核因子．κB p65亚单位（NF-κB p65）的表达，并观察肝组织病理学变化；每组均于移植肝恢复血流时收集5min的胆汁，测量5min胆汁分泌量。结果A组的5min胆汁分泌量为（3．73±1．11）μl．明显高于B组的（2．35±0．92）μ和C组的（2．23±0．81）μl（P〈0．05）。A组血清ALT含量为（468±36）IU／L．B组为（619±49）IU／L．C组为（820±65）IU／L，A组明显低于B、C组（P〈0．05），B组明显低于C组（P〈0．05）。A组血清NO含量为（14．2±1．5）μmol／L，明显高于B组的（10．5±1．2）μmol／L和C组的（10．3±1．1）μmol／L（P〈0．05）。A组肝组织中NF-κB p65表达阳性细胞百分率为（23．5±1．9）％．B组为（43．8±3．8）％，C组为（48．6±5．1）％．A组明显低于B、C组（P〈0．05）。病理学观察显示．随着移植肝脏再灌注时间的延长，肝组织损伤呈进行性加重。Pearson相关性分析提示．NO与血清ALT水平及NF-κB p65表达呈明显的负相关（r值分别为-0．74和-0．77，P〈0．01）。结论移植肝脏再灌注早期．血清NO下降，NF-κB的活性逐渐增强．移植肝脏的功能和组织损伤呈加重趋势。     

肝动脉灌注和外周静脉输注5-FU在大鼠肝脏和血液中的浓度分布的实验研究

目的探讨经肝动脉区域灌注和外周静脉注射5-FU在大鼠血液和肝脏组织中的浓度分布规律及差异。方法本研究将24只Wistar大鼠随机分为两组：A组为肝动脉灌注组;B组为外周静脉（颈静脉）输注组,分别经肝动脉插管区域灌注与经颈静脉注射5-FU,剂量为20mg/kg体重,每组均有6只大鼠取血,6只取肝组织样本。采用高效液相色谱法测定血浆及肝脏组织中5-FU的含量,并计算5-FU在肝脏和血浆中的药动学参数、穿透比率、穿透指数和相对治疗优势度。结果经外周静脉注射后肝脏组织的药物峰浓度（Cmax）和药物时量曲线下面积（AUC）分别为13.79±4.56μg/g,342.20±108.20μg·h/g;血浆Cmax和AUC分别为36.85±5.96μg/ml,842.00±158.00μg·h/ml。肝动脉灌注5-FU后肝脏组织药物Cmax和AUC分别为29.58±4.30μg/g,794.60±115.40μg·h/g;血浆Cmax和AUC分别为24.39±4.63μg/ml,639.70±133.80μg·h/ml。结论与外周静脉注射全身化疗比较,区域性肝动脉灌注5-FU可显著提高肝脏组织中的药物浓度,同时减少化疗药物在外周血中的分布。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg^?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg^?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg^?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.     

Membranes in Artificial Organs

Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.